2. Solved Papers
  3. WB JEE Medical

WB JEE Medical WB JEE Medical Solved Paper-2010

  • question_answer
    Two mirrors at an angle \[{{\text{ }\!\!\theta\!\!\text{ }}^{\text{o}}}\] produce 5 images of a point. The number of images produced when \[\text{ }\!\!\theta\!\!\text{ }\] is decreased to \[\theta -{{30}^{o}}\] is

    A)  9                                            

    B)  10

    C)  11                                         

    D)  12

    Correct Answer: C

    Solution :

                     Given the number of images = 5 So,          we have\[\frac{{{360}^{o}}}{{{\theta }^{o}}}-1=5\] \[\Rightarrow \]               \[{{\theta }^{o}}={{60}^{o}}\] when the angle is decreased to \[\theta -{{30}^{o}},\] ie, \[\theta -{{30}^{o}}={{60}^{o}}-{{30}^{o}}={{30}^{o}},\]the number of images become, \[\frac{{{360}^{o}}}{{{30}^{o}}}-1=11\]


You need to login to perform this action.
You will be redirected in 3 sec spinner